[Knowledge Share] How Circuit Breakers Work

The circuit breaker acts as a safety device in the same way
as a fuse. Circuit breakers that  are used at the distribution
board in houses are called MCBs (minature circuit breakers).
The distribution board is also called the consumer unit.
The MCBs disconnect the supply if too large a current flows.

Leakage circuit breaker

When the live wire carries the usual operating current, the

electromagnet is not strong enough to separate the contacts.

If something goes wrong with the appliance and a

large current flows, the electromagnet will pull hard enough

to separate the contacts and break the circuit.

The spring then keeps the contacts apart.

After the fault is repaired, the contacts can be

pushed back together by

lifting a switch on the outside of the circuit breaker.